Reports have indicated that maternal administration of ritodrine increased the ventricular rate and thus ameliorated signs of heart failure in a fetus with complete atrioventricular block (CAVB). A fetus from a mother without the anti-SS-A/SS-B antibody had CAVB, with atrial rate 148-154 bpm and ventricular rate 53-57 bpm. After maternal administration of ritodrine, the ventricular rate increased to 60-65 bpm, and then sinus rhythm resumed. Ritodrine may not only increase the ventricular rate but also induce sinus rhythm in a fetus with CAVB.